The following information obtained from UNAVCO's online DOI system:
(https://www.unavco.org/data/doi/search/search.html)

Philippines GPS Network - KAYT-Kaygabok Lava Flow P.S.
Start: 06-Jun-1998
End: 05-Jul-2005
Hamburger, Michael, Lowry, Tony, 1998, Philippines GPS Network - KAYT-Kaygabok Lava Flow P.S., UNAVCO, GPS/GNSS Observations Dataset, 
https://doi.org/10.7283/T5XW4H0W